1. Field of the Invention
The present invention relates to an improvement of a cleaner for the inside of a water tank, which is designed so that water stored within the water tank used for breeding or rearing and bringing up aquarium fishes such as goldfishes, tropical fishes, saltwater fishes and the like, particularly, dirty water stored in the bottom of the water tank, can be drawn up and discharged to the outside of the water tank.
2. Description of the Related Art
To breed or rear and bring up aquarium fishes such as goldfishes, tropical fishes and the like within a water tank, in general, a purifying means is provided which comprises an internal-type or external-type filter device placed in the water tank and including an air pump or an underwater pump, so that the water stored in the water tank is forcibly circulated into the filter device by driving the pump. Water having a satisfactory quality required for breeding or rearing and bringing up fishes cannot be obtained by use of only such purifying means. For this reason, it is conventionally necessary to periodically renew the water within the water tank. There is a cleaner for such renewal of the water, which is known, for example, from Japanese Patent Publication No.6-55087.
Such cleaner is designed to draw up the water within the water tank through a draw-up pipe to the outside by utilizing a siphonage, and is comprised of the hard draw-up pipe and a flexible water conduit pipe which is withdrawably connected to a base end of the draw-up pipe. The draw-up pipe includes a straight body portion having a tip end opened, and a grip portion integrally connected at substantially right angles to a base end of the body portion. Further, a single one-way valve is provided within the draw-up pipe to permit flowing of the water from the front end to the base end of the draw-up pipe. Such cleaner is widespread, because it has an advantage that dirty water within the water tank, particularly, a filth such as leftover and excrement sedimented in the bottom of the water tank can be drawn up and discharged efficiently along with the dirty water.
However, the following disadvantages have been found in the course of servicing of the above cleaner, and it has been made clear that there. is room for further improvement in the cleaner.
(1) The draw-up pipe of the cleaner is bent to form an angle of substantially 90xc2x0 between the body portion and the grip portion. Therefore, during service of the cleaner, the grip portion may hit an edge of the water tank and as a result, it may sometimes be difficult to manipulate the cleaner.
(2) Depending on the service state of the cleaner, air may remain accumulated in that upper portion of a bent section between the body portion and the grip portion which is an uppermost portion of the draw-up pipe, and this may obstruct the smooth drawing-up of the water by the siphonage.
(3) The connected portion of the flexible water conduit pipe to the draw-up pipe may be deteriorated with the passage of time, resulting in an insufficient water-tight connection of the conduit pipe to the draw-up pipe, or in slipping-off of the conduit pipe from the draw-up pipe.
(4) If the angle of bending of the connected portion of the flexible water conduit pipe to the draw-up pipe is too large, a narrower area is formed to obstruct the flowing of the water. Therefore, to prevent the above disadvantages, it is required that the connected portion of the conduit pipe is formed so that it is prevented from being bent, e.g., is formed into a double-pipe construction, thereby bringing about an increase in cost.
Accordingly, it is an object of the present invention to provide a novel cleaner for the inside of a water tank, wherein all the above-described disadvantages have been solved.
To achieve the above object, according to a first aspect and feature of the present invention, there is provided a cleaner for the inside of a water tank, which is designed to draw up water stored in the water tank by the siphonage to discharge the water to the outside of the water tank, and which comprises a draw-up pipe comprised of a straight body portion, and a grip portion connected to the body portion at 90xc2x0 or more in communication therebetween, a flexible water conduit pipe connected to a downstream end of the draw-up pipe, a first one-way valve mounted in an appropriate place within the draw-up pipe to permit flowing of water from the draw-up pipe only to the conduit pipe, and a second one-way valve mounted within the draw-up pipe at a location downstream of the first one-way valve to permit flowing of water from the draw-up pipe only to the conduit pipe. p With the above arrangement, the draw-up pipe is less likely to hit an edge of the water tank and hence, it is easy to manipulate the cleaner within the water tank. Moreover, even if the draw-up pipe is in any drawing-up attitude within the water tank, air resident within the draw-up pipe, particularly within an upper portion of the draw-up pipe can be reliably discharged to the outside along with water, and the water discharging efficiency can be enhanced.
According to a second aspect and feature of the present invention, in addition to the first feature, a joint pipe attached to the water conduit pipe is connected to a downstream end of the draw-up pipe, and a hard outer pipe is fitted over and covers an outer periphery of a connection between the drawn-up pipe and the joint pipe, so as to prevent the slip-off of the water conduit pipe by the outer pipe, and to prevent the water conduit pipe from being folded to such an extent as obstructing the flowing of water therein.
With the above arrangement, it is possible to ensure the connection of the draw-up pipe to the water conduit pipe, and to prevent the extreme folding of the flexible water conduit pipe, so that water always flows smoothly within the water conduit pipe. Thus, it is possible to enhance the water discharging efficiency.
The above and other objects, features and advantages of the invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.